“Trains are too slow, and the trip by steamship around South America would take months,” replied Roger. “We’ll take a plane.”

He logged onto the central network using his personal computer, and waited while the system verified his identity. With a few keystrokes he entered an electronic ticketing system, and entered the codes for his point of departure and his destination. In moments the computer displayed a list of possible flights, and he picked the earliest one. Dollars were automatically deducted from his personal account to pay for the transaction.